Long-term prognostic role of persistent microvascular obstruction determined by cardiac magnetic resonance for ST-segment elevation myocardial infarction.

BACKGROUND

Microvascular occlusion (MVO) determined by cardiac magnetic resonance (CMR) exists both in acute phase and recovery period after myocardial infarction. This study aimed to examine the long-term prognosis predictive value of persistent MVO for ST-segment elevation myocardial infarction (STEMI).

METHODS

A prospective cohort enrolled 344 patients with STEMI who received primary percutaneous coronary intervention and underwent CMR both in 5 to 7 days and 6 months after STEMI to determine if MVO had occurred. All patients were followed up for 5 years, and major adverse cardiovascular events (MACE) were recorded.

RESULTS

This study included 344 STEMI patients with an average age of 57 years at 6 centers in China. A total of 192 (55.81%) patients with STEMI did not have MVO by CMR, and 105 (30.52%) patients showed transient MVO in acute phase of myocardial infarction and 47 (13.66%) patients showed persistent MVO at 6 months after infarction. The patients with persistent MVO had the largest infarct size and the lowest left ventricular ejection fraction both in 5 to 7 days and 6 months after infarction (all P < .001). Patients with persistent MVO showed a significantly higher incidence of 5-years MACE than those without MVO or with MVO in only 1 week (66.0% vs 18.8% and 27.6%, respectively; P < .001). Persistent MVO was an independent strong predictor of MACE after adjustment for other CMR variables (OR: 3.912, 95% CI: 1.904-8.037; P < .001). A propensity score-matched population comprised 43 patients with persistent MVO and 43 patients with transient MVO in only 1 week. The patients with persistent MVO had a higher incidence of MACE than those with transient MVO (65.1% [28/43] vs 37.2% [16/43]; P = .010).

CONCLUSION

Persistent MVO by CMR at the chronic phase of STEMI provides useful prognostic information regarding long-term outcomes after primary percutaneous coronary intervention.